• ns1@feddit.uk
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    8 months ago

    More likely a mathematician would correct you instead of crying. Pi is not infinite, its decimal expansion is infinite!

    • zkfcfbzr@lemmy.world
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      8 months ago

      Plus even that isn’t enough: 10/3 has an infinite decimal expansion (in base 10 at least) too, but if π = 10/3, you’d be able to find exact circumferences. Its irrationality is what makes it relevant to this joke.

      A mathematician is also perfectly happy with answers like “4π” as exact.

      Plus what’s to stop you from having a rational circumference but irrational radius?

      Writing this, I feel like I might have accidentally proved your point.

      • danc4498@lemmy.world
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        8 months ago

        Mathematicians taking a physics class and being told they have to round things. That’s when the tears start flowing.

    • Carnelian@lemmy.world
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      8 months ago

      The actual punchline here should have been “there is no known equation to calculate the exact perimeter of an ellipse”, then sucking tears from an astrophysicist

    • LanternEverywhere@kbin.social
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      8 months ago

      Exactly, a fraction is completely as valid of a way to express a number as using a decimal.

      1/2 = 0.5

      They’re both fully valid ways to write the exact same quantity

    • chillhelm@lemmy.world
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      8 months ago

      This is the correct answer. Pi is known. What it’s decimal expansion looks like is irrelevant. It’s 1 in base Pi.

      • cogman@lemmy.world
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        8 months ago

        Yup, similar to the square root of two and Euler’s number.

        These are numbers defined by their properties and not their exact values. In fact, we have imaginary numbers that don’t have values and yet are still extremely useful because of their defined properties.